Clutch pack braking is a well-established method of braking vehicles and refers to using clutch packs in the transmission system to slow or brake a vehicle. Clutch pack braking is usually performed by slipping one clutch pack while locking the other clutch pack. This technique concentrates all of the energy in the slipping pack, or if both packs are slipped, can produce unpredictable slipping in both clutch packs. Also, if part throttle braking is attempted, clutch pack braking can stall the vehicle engine by turning the torque converter turbine in the transmission system backwards and overloading the engine. Thus a vehicle operator currently has to use a brake pedal to stop a vehicle at higher speeds.
Energy is wasted in power shift transmissions due to large torque converter slippage at low truck speeds. This usually happens when the vehicle is generating maximum pushing forces. This energy loss can be up to 100 percent of engine power.
The present invention addresses this and other problems associated with the prior art.